Strange Magnetohydrodynamic propelled boat smashed speed expectations.
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- Опубликовано: 11 сен 2024
- A chubby radio controlled boat with counterintuitive design sets its sights on outperforming a slender research catamaran.
MHD 1.1 specs:
Length - 335mm
Beam - 130mm
Displacement - 950g.
Efficiency - I'd rather not say.
Catamaran specs:
Length - 500mm
Displacement - 915g
More on the catamaran design can be found in the PLOS journal article "Experimental and theoretical study of magnetohydrodynamic ship models".
Instead of the battery, just a thought. Why not use a salt water battery instead and that could remain in the water which would give it almost indefinite life until the cell broke down and stopped working. I have a flashlight powered by salt water and it's worked for a year now and it's still working. Because you get better results in salty water with the MHD drive, the battery would also fair better too. Just a thought
I wasn't aware of the Yamato 1, what an absolute beast!
As per documents online about the ship, the Yamato 1 had 185T of displacement, due in no small part to the use of heavy superconducting coils, a cryostat, screw compressors, and the three generators onboard. They even had to put larger supporting equipment on shore to help charge the cryogenic helium and 4000A current in the superconducting coils to reduce Yamato 1's weight to the 185T. The vessel achieved a staggering 4167 mm/s from 16kN of force for its size and scale. It seemed like the purpose of the experimental vessel was primarily geared to making portable cryogenic superconducting MHD systems. They concluded the vessel couldn't "vie in propulsion efficiency with ships using conventional modes of propulsion." This seems very apparent, as they were using 2x2000kW (diesel?) generators to produce AC, which was stepped down to power the DC MHD and the cryostat. The efficiency of those generators and conversion losses was probably below 25% from fuel to DC before even producing thrust. The superconducting coil and refrigeration system was charged and cooled while docked with a special shore support base where the superconducting magnet would be allowed to freewheel while undocked, so only maintaining the temperature with the cryostat was required and that must have helped the system efficiency tremendously. I find it strange that the efficiency was not published, but anecdotally, if they conclude it cannot compete, its likely worse by a significant margin just as MHD is regarded today.
In the takezawa1995 closing remarks, just like in the catamaran paper you originally reference, they desired to increase magnetic field strength, surface area, and seawater conductivity to increase propulsion efficiency towards competitive viability. It seems strange to me that there was no consideration for the energy conversion efficiency of their (diesel?) generator power plants and the power consumption of the supporting systems needed to run this type of MHD vessel.
The Yamato 1 produced 842,000x more thrust than your model boat with only 72,000x more power into the water. At first this seems quite good as the Yamato 1 produced 11.7x more thrust per watt than the model did. However, if you factor in the auxiliary power required to run the support systems and assume it is loaded to 90% of its rated capacity, the comparison shrinks such that the Yamato produces only 8x more thrust per watt of power with 100% efficient generators, AC/DC converters and current regulation controllers. Further, if you factor in fuel efficiency, the Yamato 1 produces only 2x more thrust per watt than your new model with 35% efficient diesel generators (main and auxiliary), 80% efficient step down converter, and 90% efficient current regulator.
If we put that into perspective, and ignoring the impact on the displacement and size of the vessel (we assume it is perfectly scalable for time considerations), it's arguable whether stronger magnetic field strength is worth the extra power and cost requirements when permanent magnet MHD running off batteries as a current source without conversion losses offers the kind of performance you're seeing at a fraction of the price.
Yes the Yamato is a fascinating design. I will attempt to do a scaled comparison with my design and the cat in the follow-up video. The electrical power was 3.6MW at the maximum 2000A electrode current. Using that as input power, efficiency was around 1%. Modern superconductors could possibly reduce some of the cryogenic requirements but the structure keeping the coils from tearing themselves apart will remain, if not increase if even higher fields are to be created.
It is the choice of hull shape that baffles me. Much emphasis appeared to have been placed on course stability at great expense to wetted surface area.
@@williamfraser That does sound baffling. It had a rudder as a control surface and the potential for vectored thrust. Why compromise efficiency further?
Does course stability have a bigger consideration at low speed or high speed? Figure 12 of "The superconducting MHD-propelled ship YAMATO-1" extrapolated speeds to 7.5knots which should be quite a bit under hull speed. Maybe the foundation expected technology to improve such that they would swap out components and reach higher speeds on the Yamato-1 where course stability would play a factor? I.E maybe they tried to future-proof the design.
Thanks for the nice summary. I also looked at that document and I think that the highest speed that they achieved was of 6.6 kt, which is about 3.4 m/s, for 2x2 kA @ 3 T. I also think that 16 kN was the target at 4 T. if we take the inter-electrode distance of 0.175m and multiply it by 3 T, by 2 kA, and by 12, we get about 12.6 kN.
It's really cool to see it working. However, the power consumption really shows the inefficiency of this type of propulsion.
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Great video, pls keep us updated on this effort.
Отличный опыт постройки судна на электромагнитной тяге.
Нет ничего не возможного!
Double the Speed of the Cat on half the power, that's fantastic! It looks like your suspicions were correct about the efficiency of the hull and shape of your magnetic field and electrodes. Very impressed with the presentation, frame by frame displacement calculations and integrals. Michlet looks like such an amazing tool for designing and analyzing hulls.
I noticed you made the wall thickness from the magnets as thin as possible so as to remove the magnets as a flow restriction in the water but not reduce surface B field strength by much, very nice.
Am I correct in assuming the central piece of metal external to the hull at 2:11 is the aluminum? I imagine this is so you have differential steering control and can implement that extra 0.7V you talked about last year.
Looking forward to the thruster and hull design segment!
Yes the center electrode is aluminum, or what is left of it. It is corroding away at an incredible rate.
@@williamfraser Haha, well I guess you're taking the complete opposite approach to preventing galvanic corrosion. Your cathode surface area is roughly double that of the anode, increasing the rate of reduction. But if you had 2/1 aluminum/copper electrodes you wouldn't get nearly the galvanic current beneficial for MHD motoring... Any idea how much mass has been lost over the number of runs you've given MHD 1.1? As far as energy use is concerned, the embodied energy of aluminum is one of the highest in metal production. It's something like 210MJ / kg , and according to Swinburne University of Technology, modern smelters use 13.5 kWh / kg which is "about twice the theoretical amount required". Once the aluminum is near finished with, would you consider switching to Zinc? It's embodied energy is 16.9-22.8% that of aluminum and the galvanic potential is slightly more anodic at -1.00 to -1.08V. But perhaps because its embodied energy is so much lower and its density is 2.4x that of aluminum, it could represent a higher onboard energy density for the MHD 1.1.
@@williamfraser I am currently working on a similar project. I calculated and actually measured a dissolving rate of 1 mm / 16 minutes at 3 A / cm² (which is the highest current density reported in the PLOS paper). I also tested graphite electrodes. They do not seem to corrode significantly but the voltage required for the reaching the same current density is higher and it produces chlorine. Thanks for sharing your hobby, it is inspiring and helpful.
@@InfinionExperiments The loss depends directly on the current density. It is of 1 mm / 16 minutes at 3 A / cm²: 1mm x 1cm² is roughly 1/1OOth of mole of aluminum (atomic mass 27 and density 2.68). 1 mole is roughly 96500 Coulombs, multiplied by 3 because Al gives 3 electrons and divided by 3 for a current density of 3 A / cm², it gives 965 seconds for 1/1OOth of mole. I checked it experimentally, the prediction was very accurate. When aluminum anodes are used, there is very little, if any, production of chlorine so this reaction can be ignored.
@@georgesquenot1404 I thought chlorine was only produced at the negative electrode?
Perhaps a swimming pool early in the morning while very still would be a good test area? Also, you've seen Tech Ingredients youtube channel on this topic, right?
I'm thinking you should use a kayak to build the next model.
There is no question about it, it has to be done! Even if it is guaranteed to be utterly impractical. I need to start saving up for more magnets...
@@williamfraser Would it help to use some sort of capacitor to dump more power (increase voltage as well?) at once for more acceleration then have a catamaran style craft for less drag.
nice video really like the way you do the measurements and show graphs...just curious have you tried experiementing with halbach arrays ? so my guess would be using a halbach array, you should get more dense uniform stronger magnetic field close to the electrodes resulting in the stronger force experienced by water giving a higher thrust...
I haven't tried a Halbach array but it should work. I tried a steel plate flux bridge. Acceleration was the same, so the thrust must have increased to make up for the additional mass.
Yo
mitsubishi actually wanted to build AC MHD propulsion and they calculated 100 knots cause with AC MHD you can avoid electrolosys which you cant do with DC system. They were STOPPED by going AC MHD probably cause high frequency AC MHD with low work function materials (lower than infra red or perhaps adding a heating element for electrons could work too) propulsion becomes INERTIAL propulsion
Mike McCullough is doing just capacitator experiments without magnets and getting better propulsion than nasa
Interesting. I noticed that AC was considered for the Yamato but DC was chosen for its suitability to be used with superconductor coils. I need to take a closer look at the AC design.
Is Mike McCullough's research in any way similar to that of Jean Louis Naudin?
@@williamfraser I didnt hear about that name yet, but i really suggest you check his stuff.
Got 3 or 4 good videos on youtube although mostly the same in each video you uncover more stuff.
Main point is he fixed dark matter which is awesome by itself!
@@williamfraser Here a video with some math (better than TED talks video)
ruclips.net/video/Pc-AOBj7jxI/видео.html
That's interesting. Popular Mechanics discussed the 100-knot superboat in their August 1990 issue on their website. They don't go into any substantial detail, let alone AC MHD or Mitsubishi, and yet the 100-knot figure is headlined, its association with anything plunged into obscurity, heresay, and science fiction. These popular science magazines existed to sensationalize technologies to the public. That sensationalism is the basis for the important perception of scientific progress with the public. It feels like a careful and clever strategy to then diffuse the technology to require scientific progress and decades of funding opportunities to stifle true mastery and disruptiveness to the modern world. Maybe because its masters don't like sharing what they have already.
But I digress, without magnets, it sounds like Mike McCullough is playing with what would be categorized as Electrohydrodynamics ( a nod to Bibhas De, a lesser known doctoral student of Hannes Alfven, father of MHD).
Fly fishermen and fishermen in general would BUY this big time.
Ek hoop jou patent papiere is reg! :)
Top job, lad!
Thanks pal. Now I just need to finish the technical explanation and theory vids. This project has been mental, I need a fishing break.
try a water tunnel, where the water moves not the boat, to get the max speed :)
you could make it as a water wheel paddle water moving tunnel
Well, catamarans are not always the fastest, especially when we have the same displacement.
For displacement hulls, there are 2 types of drag:
1.Skin drag is just the friction of water molecules against the surface.
2. Wave making drag which is basically energy lost to creating wake, or trying to drive the hull over it's own wake.
Skin drag is minimised by minimising surface area. However, the minimum area for a given displacement is a hemisphere, but that is not good for wave making drag. Wave making drag is low at low speeds & increases very gradually until the hull gets to a speed close to than of a wave of the same length as the hulls waterline length. As this speed is approached, wave drag rises very steeply to the point of imposing a speed limit on the hull. This is hull speed, & is a function of the hulls length & its fineness ratio. Cats have a finer hull, so they have a higher hull speed than a monohull of the same length. That is not how we design boat hulls though. We design a hull for a speed and displacement, ore for a power and displacement. We don't design a hull to go faster than is needed, but we may design it to go as fast s possible for the available power & displacement. Also stability and sea keeping of course, but that'ballast
Very well summarized. I have yet to grasp the reasoning behind the design of the Yamato 1 hull. Yaw stability seems to have been one of the driving factors following model tow tank tests. Wetted area is ridiculously high.
@@williamfraser IMO, Yamato 1, looks like an existing production design that has had drive pods added each side. Probably less expensive than doing a fully integrated 1 off design. Without the pods, it appears to be a heavy planning hull design for big seas. Heavy boats require a lot of wetted area to provide sufficient lift to overcome the transition phase. Light weight planning hulls, such as sailing race skiffs, have practically no transition drag hump at all, as they start to lift (reducing wetted surface) in the upper end of their displacement range, but heavy hulls lift the bow & drag the transom in high drag during transition.
Yamato 1 doesn't look like a purpose design for 8 kts. A heavy displacement hull (beamy) would need about 36 feet (11m) LWL. A light weight narrow displacement would need a little less LWL.
However, I haven't read the development of Yamato 1, let alone studied it. My comments here are pure conjecture based on the photographs a google search showed.
hi sir, im super interested in this prototype. and i wan to pursue this project. may I consult u for more information please thanks?
Sure.
Joule thief circuit. could increase the voltage and gain more autonomy?
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The Joule thief uses pulses to boost voltage but the average output current decreases. The MHD thrust depends on average current so I don't think the Joule thief will help.
Молодец!
The US Navy did the same research in the 1980s on MHD. JUST GOOGLE IT and save your trial and Errors efforts.
Electrolysis in sea salt water, solar and piezoelectric panel in sea waves. would it be viable and possible?
The hydrogen produced by electrolysis could be captured and used in a fuel cell. Solar power would help, I still want to test a model. Piezo power generation is very inefficient but I guess every bit of power helps if the cost can be justified.
love this video!
i am doing a school project on a boat prototype powered by magneto hydrodynamic. would appreciate it if you could drop your email to ask you more questions in detail
Aircraftworx@yahoo.co.uk
Hi William. I am preparing a video about a boat with a different thruster design, partly inspired by yours. I plan to refer to your boat as you did with the ISTerre catamaran. For comparison purposes, can you please tell me the exact size of the magnets that you used as well as their spacing? I also have the same question for the electrode sizes. Thanks.
Magnets are N52, 50x20x8, six total (three stacked per side. Electrodes are 22x68, ballpark.
@@williamfraser I just released a video about my thruster and boat: ruclips.net/video/IYibLoznmNg/видео.html
This is not yet the one in which I evaluate and compare various designs, including yours.
Have you considered using higher voltage dc pulsed to keep power usage down and use the inertia in the water itself.😢
What you need is a hull that rides its own wake.
I calculate less than a ¼ mile per hour. Hull speed on my 36' sailboat is 7 knts
Have you tried lead foil for the electrodes? Lead oxide is conductive and protective of the metal?
Also, is it possible to use ac inductance to generate current in the water and ac coil’s to repel the water? I’m trying to think of a way to prevent the corrosion problems with metallic hulls
No I haven't considered lead, I'll have to give it a try.
@@ANATURALDREWSASTER yes I believe it has been tried and that it does work. The PLOS article references a number of other projects, there might be an example among them.
I guess this only works well in seawater? Not so well in fresh water due to low conductivity?
Absolutely correct. Thrust depends on electric current through the water so the voltage will need to be much higher for fresh water.
Sounds like a... magma displacement?
Has anyone tried coil magnets so the field can be varied?
The Yamato 1 used superconducting coils but the field was not varied during operation. They did test at different field strength on separate tests. To vary thrust the electrode current was varied.
U don´t need to vary the field, since u can already vary the current of the electrodes... Electromotors are made of permenent and electormagnets, for a reason... Why use 2 electromagnets, when using only one brings the same profit?
@@klausbrinck2137 weight, material cost, and regulation. A car alternator, for example, regulates the output voltage by varying the current through the exciter coils, since the speed of the engine is independent. AC induction motors also don't use any permanent magnets. They're not as efficient, but ridiculously cheap to make.
@@DFPercush Yeah, but here it is all a piece of show and R+D, so, cost shouldn´t be an issue.
Пузырьками "отталкивается" 😊 !?
Is very fast if you think dath the waves are gigantic
Hi william new sub am loving the channel wish id have found it sooner. Could i send you a video (YT link) and ask for your assistance please?its for a solar powered motor (washing machine motor rewired to run off 12 volts dc) and what i could do with it power wise. Cheers mac
Sure, I don't have any experience with washing machine motors but I'm happy to take a look.
@@williamfraser cool thanks, its very easy to do, i have also made one which you use as a generator and the idea is to combine the two. I will post both links here below, many thanks.
ruclips.net/video/rQDjrldTeIo/видео.html
Washing machine motor running off solar panel, think how powerful a washing machine motor is, has to be anchored down (the machine)
ruclips.net/video/RvH0PB1o1v4/видео.html
Second one what i intend to do with the first one hopefully, as in use that motor powered by solar panels to turn this deisgn^ to power all manner of things as shown in the video :).
Cheers
Mac
@@williamfraser removed my second comment with another link so ill upload it again, spin a wm motor for long enough for it to register charging on the inverter and you can remove the drill and it spins all by itself for a full 15 minutes every time,ive tried cooling it, starting it immediately again afterwards and discovered its not shutting off due to temperature as its the same every single time.
ruclips.net/video/whs8anrc9fs/видео.html
Interesting. I don't have an inverter but I'll see what happens if I try it with my charge controller.
@@williamfraser go for it buddy or just hook it straight up to a 12 volt battery or better 24 volt battery bank :). Tbf all ive done is put the wires connected to the motor on the terminals connecting my solar panels (5 in parallel) to the inverter. I can put those wires in my solar panel connection box and it doed the same so no inverter required really
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